In recent years, research and development of resistance change memories such as PCM and ReRAM is actively conducted. Such resistance change memories have a large ratio of the resistance in a high-resistance state to that in a low-resistance state of about two to five orders of magnitude and are promising as a nonvolatile memory device.
However, conventional resistance change memories have a problem of large write currents. Thus, an IR drop caused by resistance of word lines and bit lines increases so that the number of memory cells that can be connected to one word line and one bit line is limited. Therefore, there arises a problem that the number of cells contained in a memory cell array cannot be increased.
As a factor of the above problem, a selected memory element cannot be efficiently heated because heat is dissipated from the selected memory element into its surroundings.
Therefore, a nonvolatile memory device capable of efficiently heating the selected memory element is desired.